Copper. Copper has been used in various ways in art due to its versatility, durability, and aesthetic properties. Copper was used as a support for oil paintings due to its smooth, non-porous surface, which allowed for exceptionally fine detail and vibrant colors. Copper and its alloys, such as bronze and brass, have been widely used for creating sculptures. Copper's malleability and strength make it suitable for casting intricate and detailed sculptures, while its natural patina adds an attractive, aged appearance over time. Copper has been employed in the creation of decorative objects, such as vases, bowls, and candlesticks, as well as functional items like door handles and other hardware. Copper's ability to be hammered, engraved, and etched allows for the creation of intricate designs and patterns. It has been a popular material for printmaking, particularly in the techniques of etching and engraving. The relatively soft metal allows for detailed lines and textures to be incised, which can then be inked and printed onto paper or other surfaces. Copper has been a popular material for printmaking, particularly in the techniques of etching and engraving. The relatively soft metal allows for detailed lines and textures to be incised, which can then be inked and printed onto paper or other surfaces. Copper was used as a support for oil paintings due to its smooth, non-porous surface, which allowed for exceptionally fine detail and vibrant colors. The smooth surface of copper plates provided an ideal foundation for artists to create highly detailed and intricate compositions. Copper's lack of texture allowed for the creation of precise lines and crisp edges, which were particularly suited to small-scale paintings and miniatures. Copper is a durable and stable material that is resistant to warping, cracking, and the effects of moisture. This made it an attractive alternative to traditional painting supports like wood panels or canvas, which could be prone to deterioration over time. The non-porous nature of copper meant that oil paints did not absorb into the surface, allowing the colors to maintain their vibrancy and intensity. This resulted in paintings with luminous and richly saturated hues. Copper is a chemical element; it has symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form. This led to very early human use in several regions, from c. 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, c. 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create bronze, c. 3500 BC. In the Roman era, copper was mined principally on Cyprus, the origin of the name of the metal, from aes cyprium, later corrupted to cuprum. Coper and copper were derived from this, the later spelling first used around 1530. Commonly encountered compounds are copper salts, which often impart blue or green colors to such minerals as azurite, malachite, and turquoise, and have been used widely and historically as pigments. Copper used in buildings, usually for roofing, oxidizes to form a green patina of compounds called verdigris. Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as bacteriostatic agents, fungicides, and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the respiratory enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the iron-complexed hemoglobin in fish and other vertebrates. In humans, copper is found mainly in the liver, muscle, and bone. The adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight.